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You searched for: subject:"finite element method"
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[texts]What Is a Good Linear Finite Element? - Jonathan
Why are elements with tiny angles harmless for interpolation, but deadly for stiffness matrix conditioning? Why are long, thin elements with angles near 180o terrible in isotropic cases but perfectly acceptable, if they're aligned properly, for anisotropic PDEs whose solutions have anisotropic curvature? Why do elements that are too long and thin sometimes offer unexpectedly accurate PDE solutions? Why can interpolation error, discretization error, and stiffness matrix conditioning sometimes hav...
Keywords: Finite element method
Downloads: 39
[texts]Evaluation of flood risk factors in the design of highway stream crossings : V.3, Finite element model for bridge backwater computation - Water Resources Engineers, Inc
PB 254 960/AS
Keywords: Finite element method; Hydraulics
Downloads: 46
[texts]On the axiomatic foundations of dimensional analysis - Gawain, Theodore Henry.
Title from cover
Keywords: FINITE ELEMENT METHOD--COMPUTER PROGRAMS
Downloads: 89
[texts]Effects of cavitation on underwater shock loading - plane problem : final report - Newton, R. E. (Robert Eugene)
Final report for period October 1979-September 1980.
Keywords: GIRDERS--VIBRATION--MATHEMATICAL MODELS; FINITE ELEMENT METHOD
Downloads: 64
[texts]Design of Pipelines Against Ice Scour: Effects of Seabed Geology
In recent years, several computational models were published for the analysis of pipelines subjected to ice scour. With one exception, most of these models assumed uniform seabed soil properties. This paper studies the effects of different seabed soil stratigraphies on the ice scour process. Influence of various stiffer and softer soil sequences on the pipeline stresses are analyzed. Effects of reworking or remolding of soils by recurrent scours are studied...
Keywords: Pipelines; Ice Scour; Finite Element Method
Downloads: 18
[texts]An efficient iterative procedure for use with the finite element method (Volume Report (University of Illinois at Urbana-Champaign. Dept. of Computer Science) no. 600) - Kim, Yong-jip, 1935-
Vita
Keywords: Differential equations, Elliptic; Finite element method
Downloads: 256
[texts]9. Eng The Modernization Of Gear Micropump Casing With The Use Of Finite Waclaw Kollek - Wacław Kollek & Urszula Radziwanowska
This paper presents the results of modernization of gear micropump casing in order to achieve minimization of overall dimensions and mass of the construction. Three different cases of the pump casing size were analyzed during numerical simulations with the use of finite element method (FEM). The dimensions of the first of the casings were identical to prototype unit, the second model was characterized by 15% reduction in size and the third casing was reduced by 25%...
Keywords: Gear Micropump; Pump Casing; Finite Element Method
Downloads: 3
[texts]The generalized element method (Volume Report (University of Illinois at Urbana-Champaign. Dept. of Computer Science) no. 946) - Speelpenning, B
"COO-2383-0055."
Keywords: Equations, Simultaneous; Matrices; Finite element method
Downloads: 38
[texts]Simulation of an Austenite-twinned-Martensite interface (Volume 108) - Kearsley, A.J.
Journal of Research of the National Institute of Standards and Technology
Keywords: finite element method; Austenite-Martensite interface; quasi-Newton method
Downloads: 88
[texts]The Navy's educational programs in electronic warfare - Hoisington, D. B. (David B.);Thomas, C.J.
Title from cover
Keywords: NUMERICAL WEATHER FORECASTING--MATHEMATICAL MODELS; FINITE ELEMENT METHOD; BAROTROPIC MODELS
Downloads: 56
[texts]NASA Patent Abstracts Bibliography: A Continuing Bibliography - NON
This report lists NASA patent abstracts recently announced in the NASA STI Database.
Keywords: CLOCKS; BOUNDARY CONDITIONS; ACCURACY; FINITE ELEMENT METHOD; SYSTEMATIC ERRORS
Downloads: 171
[texts]Observational Requirements for High-Fidelity Reverberation Mapping - Horne, Keith
We present a series of simulations to demonstrate that high-fidelity velocity-delay maps of the emission-line regions in active galactic nuclei can be obtained from time-resolved spectrophotometric data sets like those that will arise from the proposed Kronos satellite. While previous reverberation-mapping experiments have established the size scale R of the broad emission-line regions from the mean time delay tau = R/c between the line and continuum variations and have provided strong evidence ...
Keywords: CONCURRENT PROCESSING; FINITE ELEMENT METHOD; DISPLACEMENT; FACTORIZATION; OPTIMIZATION; ALTERNATIVES; COMPUTERS
Downloads: 86
[texts]Measuring Directional Wave Spectra and Wind Speed with a Scanning Radar Altimeter - Walsh, E. J.
The geometry for the NASA Scanning Radar Altimeter (SRA) is shown. It transmits a 8-ns duration pulse at Ka-band (8.3 mm) and measures time of flight as it scans a 1 degree (two-way) beam from left to right across the aircraft ground track. The most recent configuration determines the surface elevation at 64 points spaced at uniform angular intervals of about 0.7 across a swath whose width is about 0.8 times the aircraft altitude...
Keywords: PIEZOELECTRICITY; ACTUATORS; FINITE ELEMENT METHOD; DISPLACEMENT; ELECTRIC POTENTIAL; ANALOGIES; THICKNESS
Downloads: 94
[texts]A modal analysis of the violin using MSC/NASTRAN and PATRAN - Knott, George Anthony.
Thesis (M.S. in Engineering Acoustics) Naval Postgraduate School, March 1987
Keywords: Computer-aided design; Finite element method--Computer programs; Computer simulation
Downloads: 500
[texts]Optimum design of a ceramic tensile creep specimen using a finite element method (Volume 102) - Wang, Z
Journal of Research of the National Institute of Standards and Technology
Keywords: optimum design; ceramics; finite element method; stress analysis; stress relaxation
Downloads: 103
[texts]Ball motion in a ball-obturated tubular projectile - Nunn, R. H. (Robert H.);Bloomer, James Wayne.
Final report for period ending 31 December, 1980.
Keywords: ORDNANCE TESTING--MATHEMATICAL MODELS; GUNNERY--MATHEMATICAL MODELS; FINITE ELEMENT METHOD
Downloads: 74
[texts]Integrated approach to cavity system seismic evaluation - Dendrou, Basile
Final report;issued October 1978
Keywords: Earthquakes; Underground construction; Rock mechanics; Finite element method
Downloads: 68
[texts]Effect of the Human Eye Cornea Material Property on Measurement of the Intraocular Eye Pressure Utilizing Goldmann Applanation Tonometer
A quarter 3D model of cornea-aqueous humoremploying elastic anisotropic formulation in collaborationwith Goldmann appalanation tonometer (GAT) action isinvestigated in order to examine the relation between thematerial property variation and the deviation from the truepressure inside the human eye utilizing finite elementmethod. In addition to that, the effect of the corneal thicknessvariation has also been studied...
Keywords: intraocular pressure; tonometer; corneal thickness; anisotropy; finite element method
Downloads: 17
[texts]Finite element modeling of static indentation damage in laminated composites - Jung, Han Soo
Typescript
Keywords: Laminated materials; Composite materials; Composite materials; Finite element method
Downloads: 254
[texts]Laser Incident in the NASA Unitary Plan Wind Tunnel - George, Michael W.
A viewgraph presentation describing the laser incident in the NASA Unitary Plan Wind Tunnel (UPWT) is shown. The topics include: 1) Unitary Plan Wind Tunnel (UPWT); 2) UPWT 11' x 11' Transonic Wind Tunnel; 3) UPWT 9' x 7' Supersonic Wind Tunnel; 4) 3D Particle Image Velocimetry (PIV); 5) PIV System in 11' x 11' Transonic Test Section; 6) PIV installation in 11' x 11' TWT; 7) 3 Space Shuttle Ascent Configuration Test in UPWT 9' x 7' Test Section; 8) PIV installation in 9' x 7' SWT; 9) PIV Laser S...
Keywords: SOLAR SAILS; ACTUATORS; CONTROLLERS; AEROSPACE SYSTEMS; FINITE ELEMENT METHOD; STABILITY
Downloads: 96
[texts]Simulations of molecules and processes in the synapse - Kaihsu Tai
Doctoral dissertation by Kaihsu Tai; Department of Chemistry and Biochemistry, University of California, San Diego, 2002. (ISBN 0-493-90932-X)
Keywords: acetylcholinesterase; fasciculin; finite element method; molecular dynamics; neuromuscular junction
Downloads: 360
[texts]Design and analysis of a multi-backend database system for performance improvement, functionality expansion and capacity growth. part I - Hsiao, David K., 1933-;Menon, M. Jaishankar.
Title from cover
Keywords: FINITE ELEMENT METHOD; GEOSTROPHIC CURRENTS; ATMOSPHERIC PHYSICS--MATHEMATICAL MODELS
Downloads: 52
[texts]Analysis of a two-fluid EHD power generator including effects of compressibility - Gawain, Theodore Henry.;Biblarz, Oscar.
Title from cover
Keywords: DIFFERENTIAL EQUATIONS--NUMERICAL SOLUTIONS; FINITE ELEMENT METHOD; MATRICES
Downloads: 41
[texts]Simulations of molecules and processes in the synapse (slides) - Kaihsu Tai
Slides for the defense of doctoral dissertation by Kaihsu Tai; Department of Chemistry and Biochemistry, University of California, San Diego, 2002.
Keywords: acetylcholinesterase; fasciculin; finite element method; molecular dynamics; neuromuscular junction
Downloads: 96
[texts]CONVERGENCE OF ADAPTIVE MIXED FINITE ELEMENT METHOD FOR CONVECTION-DIFFUSION-REACTION EQUATIONS
We prove the convergence of an adaptive mixed finite element method (AMFEM) for (nonsymmetric) convection-diffusion-reaction equations. The convergence result holds from the cases where convection or reaction is not present to convection-or reaction-dominated problems. A novel technique of analysis is developed without any quasi orthogonality for stress and displacement variables, and without marking the oscillation dependent on discrete solutions and data...
Keywords: convection-diffusion-reaction equation; adaptive mixed finite element method; quasi orthogonality; oscillation; convergence
Downloads: 8
[texts]Safer Liquid Natural Gas - NON
After the disaster of Staten Island in 1973 where 40 people were killed repairing a liquid natural gas storage tank, the New York Fire Commissioner requested NASA's help in drawing up a comprehensive plan to cover the design, construction, and operation of liquid natural gas facilities. Two programs are underway. The first transfers comprehensive risk management techniques and procedures which take the form of an instruction document that includes determining liquid-gas risks through engineering...
Keywords: CERAMICS; FINITE ELEMENT METHOD; SILICON NITRIDES; THERMAL STRESSES; TURBINE ENGINES; COATINGS; TEMPERATURE EFFECTS; THERMAL CONDUCTIVITY
Downloads: 19
[texts]Surface Flow Visualization on a Hovering Tiltrotor Blade - Yamauchi, Gloria K.
Fluorescent mini-tufts were used to visualize the flow behavior on the upper surface of the blade of a full-scale, hovering XV-15 tiltrotor installed in the Ames 80- by 120-Foot Wind Tunnel. The objectives of the test were to determine whether the flow direction could be deduced from the tuft motion and whether this visualization technique could be practically implemented for forward flight. A dual camera/strobe system was used to acquire inboard and outboard images of approximately 2500 tufts o...
Keywords: STRESS CONCENTRATION; SOLAR SAILS; FINITE ELEMENT METHOD; THIN FILMS; WRINKLING; DEFORMATION; COMPUTATIONAL GRIDS; MEMBRANES; NONLINEARITY
Downloads: 24
[texts]An Introduction to Markov Modeling: Concepts and Uses - Boyd, Mark A
Kharkov modeling is a modeling technique that is widely useful for dependability analysis of complex fault tolerant systems. It is very flexible in the type of systems and system behavior it can model. It is not, however, the most appropriate modeling technique for every modeling situation. The first task in obtaining a reliability or availability estimate for a system is selecting which modeling technique is most appropriate to the situation at hand...
Keywords: COMPOSITE STRUCTURES; CYLINDRICAL SHELLS; VOIDS; COMPRESSION TESTS; FINITE ELEMENT METHOD; BUCKLING
Downloads: 117
[texts]An atlas of upper tropospheric radiances observed in the 6 to 7-micrometer water vapor band using TOVS data from the NOAA weather satellites during 1979-1991 - Chesters, Dennis
This document is a pictorial atlas of the Earth's radiance emitted in the 6 to 7 micro-m water vapor band. At these wavelengths, the infrared brightness temperature corresponds to the layer-average temperature of the top few millimeters of water vapor in the atmosphere. At low altitudes, bright regions are dry slots in the upper troposphere. The satellite observations were obtained from NOAA's cloud and angle corrected measurements made by a series of polar orbiting TOVS (TIROS Operational Verti...
Keywords: FINITE ELEMENT METHOD; NASTRAN; STRUCTURAL ANALYSIS; COMPUTER PROGRAMS; CONFERENCES; USER REQUIREMENTS
Downloads: 69
[texts]Performance Characterization of Digital Optical Data Transfer Systems for Use in the Space Radiation Environment - Reed, Robert A.
Radiation effects in photonic and microelectronic components can impact the performance of high-speed digital optical data link in a variety of ways. This segment of the short course focuses on radiation effects in digital optical data links operating in the MHz to GHz regime. (Some of the information is applicable to frequencies above and below this regime) The three basic component level effects that should be considered are Total Ionizing Dose (TID), Displacement Damage Dose (DDD) and Single ...
Keywords: MIRRORS; MOUNTING; ASSEMBLING; GRAVITATIONAL EFFECTS; TELESCOPES; NEXT GENERATION SPACE TELESCOPE PROJECT; FINITE ELEMENT METHOD
Downloads: 89
[texts]Dual Mode Shock-Expansion/Reflected-Shock Tunnel - Erdos, John I.
NASA s HYPULSE facility at GASL has been reconfigured to permit free jet testing of the Hyper-X flowpath at flight Mach numbers of 7 and 10. Among the required changes are addition of a converging-diverging nozzle to permit operation in a reflected shock tunnel mode, a 7 ft. diameter test cabin and a 30 in. diameter contoured nozzle. However, none of these changes were allowed to interfere with rapid recovery of the prior shock-expansion tunnel mode of operation, and indeed certain changes shoul...
Keywords: KRIGING; DESIGN ANALYSIS; MODELS; MULTIDISCIPLINARY DESIGN OPTIMIZATION; COMPUTATIONAL FLUID DYNAMICS; ERROR ANALYSIS; FINITE ELEMENT METHOD; POLYNOMIALS
Downloads: 112
[texts]Semiannual Report, 1 September 1974 - 28 February 1975 - Smith, H. J
No Abstract Available
Keywords: COMPUTATION; COMPUTER PROGRAMS; DYNAMIC STRUCTURAL ANALYSIS; FINITE DIFFERENCE THEORY; FINITE ELEMENT METHOD; NONLINEAR PROGRAMMING
Downloads: 57
[texts]Serrated-Planform Lifting-Surfaces - NON
A set of serrated-planform lifting surfaces is provided which produces unexpectedly high lift coefficients at moderate to high angles-of-attack. Each serration, or tooth, is designed to shed a vortex. The interaction of the vortices greatly enhances the lifting capability over an extremely large operating range. Variations of the invention use serrated-planform lifting surfaces in planes different than that of a primary lifting surface...
Keywords: TETHERING; FINITE ELEMENT METHOD; TOWED BODIES; COMPUTER PROGRAMS; STRUCTURAL ANALYSIS; GLIDERS; METEOROLOGICAL PARAMETERS; FLIGHT ALTITUDE; CABLES
Downloads: 107
[texts]SLICER Airborne Laser Altimeter Characterization of Canopy Structure and Sub-canopy Topography for the BOREAS Northern and Southern Study Regions: Instrument and Data Product Description - Harding, D. J.
SLICER data were acquired in support of BOREAS at all of the TF sites in the SSA and NSA, and along transects between the study areas. Data were acquired on 5 days between 18-Jul and 30-Jul-1996. Each coverage of a tower site is typically 40 km in length, with a minimum of 3 and a maximum of 10 lines across each tower oriented in a variety of azimuths. The SLICER data were acquired simultaneously with ASAS hyperspectral, multiview angle images...
Keywords: CONCENTRATORS; INFLATABLE STRUCTURES; ADAPTIVE CONTROL; VIBRATION TESTS; FINITE ELEMENT METHOD; SOLAR THERMAL PROPULSION; RELIEF VALVES; REGULATORS
Downloads: 159
[texts]Erratum: Voyager Color Photometry of Saturn's Main Rings - Estrada, Paul R.
We correct a calibration error in our earlier analysis of Voyager color observations of Saturn's main rings at 14 deg phase angle and present thoroughly revised and reanalyzed radial profiles of the brightness of the main rings in Voyager G, V, and UV filters, and ratios of these brightnesses. These results are consistent with more recent HST results at 6 deg phase angle, once allowance is made for plausible phase reddening of the rings...
Keywords: SPACE SHUTTLE BOOSTERS; BUCKLING; FAILURE; FULL SCALE TESTS; SPACE SHUTTLES; FINITE ELEMENT METHOD; PREDICTIONS
Downloads: 100
[texts]Flow control through the use of topography (Volume 112) - Kearsley, A. J.
Journal of Research of the National Institute of Standards and Technology
Keywords: finite element method; complex boundary; Taylor-Couette flow; optimization; flow control; fluid dynamics
Downloads: 136
[texts]Investigation of Sea-Level Performance of I-16 Turbojet Engine at Zero Ram with XFR-1 Intake Duct Shroud, and Tail Pipe - Dowman, Harry W.
The sea-level performance of I-16 turbojet engine at zero ram was investigated to determine the effects of an intake duct, shroud, and tail pipe intended for installation in an XFR-1 airplane. Engine speeds ranged from 8000 to 16,500 rpm for several variations of the intake duct and tail pipes.
Keywords: MEMBRANE STRUCTURES; SOLAR SAILS; WRINKLING; MODELS; NONLINEARITY; COMPUTER PROGRAMS; FINITE ELEMENT METHOD; DEFORMATION; LAGRANGIAN FUNCTION
Downloads: 77
[texts]Critical Velocity in Open Capillary Channel Flows - Rosendahl, Uwe
We investigate forced liquid flows through open capillary channels with free surfaces experimentally. The experiments were performed under low gravity conditions in the Bremen Drop Tower and on board the sounding rocket TEXUS-37. Open capillary channels (vanes) are used in surface tension tanks to transport the propellant and to provide a flow path for the bubble-free liquid supply to the thrusters...
Keywords: OPTIMIZATION; LARGE SCALE INTEGRATION; ENGINEERING; SYSTEMS SIMULATION; FINITE ELEMENT METHOD; ITERATIVE SOLUTION; GALERKIN METHOD; DISCRETIZATION (MATHEMATICS)
Downloads: 76
[texts]Entropy condition satisfying approximations for the full potential equations of transonic flow - Osher, S.
A class of conservative difference approximations for the steady full potential equation was presented. They are, in general, easier to program than the usual density biasing algorithms, and in fact, differ only slightly from them. Rigorous proof indicated that these new schemes satisfied a new discrete entropy inequality, which ruled out expansion shocks, and that they have sharp, steady, discrete shocks...
Keywords: COMPRESSIBLE FLOW; EULER EQUATIONS OF MOTION; FOURIER ANALYSIS; FINITE DIFFERENCE THEORY; FINITE ELEMENT METHOD; NOZZLE GEOMETRY
Downloads: 127
[texts]The establishment of a new method of estimating the number of advancements in the Navy enlisted force - Milch, Paul R.
Title from cover
Keywords: FINITE ELEMENT METHOD--MATHEMATICAL MODELS.NUMERICAL WEATHER FORECASTING.CYCLONES--MATHEMATICAL MODELS.NUMERICAL WEATHER FORECASTING--MATHEMATICAL MODELS
Downloads: 53
[texts]Flight Test Analysis of the Forces and Moments Imparted on a B737-100 Aircraft During Wake Vortex Encounters - Roberts, Christopher L.
Several of our major airports are operating at or near their capacity limit, increasing congestion and delays for travelers. As a result, the National Aeronautics and Space Administration (NASA) has been working in conjunction with the Federal Aviation Administration (FAA), airline operators, and the airline industry to increase airport capacity and safety. As more and more airplanes are placed into the terminal area the probability of encountering wake turbulence is increased...
Keywords: ACCURACY; WAVEGUIDES; PRESSURE DISTRIBUTION; LININGS; SOUND PRESSURE; IMPEDANCE MEASUREMENT; CERAMICS; FINITE ELEMENT METHOD; GRAZING FLOW
Downloads: 118
[texts]The Evaluation of Two CDU Concepts and Their Effects on FMS Training - Abbott, Terence S
One of the biggest challenges for a pilot in the transition to a ''glass'' cockpit is understanding the Flight Management System (FMS). This is due to both the complex nature of the FMS and to the pilot-FMS interface. For these reasons, a large portion of transition training is devoted to the FMS. The intent of the current study was to examine the impact of the primary pilot-FMS interface, the Control Display Unit (CDU), on FMS training...
Keywords: DESIGN ANALYSIS; AIRCRAFT DESIGN; FLIGHT OPTIMIZATION; PASSENGERS; CENTERBODIES; FINITE ELEMENT METHOD
Downloads: 82
[texts]Modeling of Chill Down in Cryogenic Transfer Lines - Cross, Matthew F.
A numerical model to predict chill down in cryogenic transfer lines has been developed. Three chill down cases using hydrogen as the working fluid are solved: 1) a simplified model amenable to analytical solution, 2) a realistic model of superheated vapor flow, and 3) a realistic model of initially subcooled liquid flow. The first case compares a numerical model with an analytical solution with very good agreement between the two...
Keywords: STRESS ANALYSIS; GEARS; GEAR TEETH; COMPUTER AIDED DESIGN; COMPUTER PROGRAMS; FINITE ELEMENT METHOD; MECHANICAL DRIVES
Downloads: 210
[texts]New Reduced Two-Time Step Method for Calculating Combustion and Emission Rates of Jet-A and Methane Fuel With and Without Water Injection - Molnar, Melissa
A simplified kinetic scheme for Jet-A, and methane fuels with water injection was developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) or even simple FORTRAN codes that are being developed at Glenn. The two time step method is either an initial time averaged value (step one) or an instantaneous value (step two). The switch is based on the water concentration in moles/cc of 1x10(exp -20)...
Keywords: SOLAR SAILS; MEMBRANE STRUCTURES; GRAVITATIONAL EFFECTS; KAPTON (TRADEMARK); INFLATABLE SPACE STRUCTURES; PHOTOGRAMMETRY; FINITE ELEMENT METHOD
Downloads: 92
[texts]Recommended Priorities for NASA's Gamma Ray Astronomy Program 1999-2013 - Carol, Lad
The Gamma-Ray Astronomy Program Working Group (GRAPWG) recommends priorities for the NASA Gamma-Ray Astronomy Program. The highest priority science topic is nuclear astrophysics and sites of gamma ray line emission. Other high priority topics are gamma ray bursts, hard x-ray emission from accreting black holes and neutron stars, the Advanced Compton Telescope (ACT), the High-resolution Spectroscopic Imager (HSI), and the Energetic X-ray Imaging Survey Telescope (EXIST)...
Keywords: COMPOSITE STRUCTURES; BUCKLING; FINITE ELEMENT METHOD; FAILURE ANALYSIS; PANELS; DEGRADATION; DAMAGE; DEFECTS; OPENINGS
Downloads: 176
[texts]Textbook Multigrid Efficiency for the Steady Euler Equations - Roberts, Thomas W.
A fast multigrid solver for the steady incompressible Euler equations is presented. Unlike time-marching schemes, this approach uses relaxation of the steady equations. Application of this method results in a discretization that correctly distinguishes between the advection and elliptic parts of the operator, allowing efficient smoothers to be constructed. Solvers for both unstructured triangular grids and structured quadrilateral grids have been written...
Keywords: STRUCTURAL ANALYSIS; FUSELAGES; PANELS; FINITE ELEMENT METHOD; ELECTRO-OPTICS; HOLOGRAPHY; INTERFEROMETRY; IMAGE PROCESSING
Downloads: 113
[texts]MSFC Investigations of Beta Cloth Darkening Due to Ultraviolet Radiation Interactions - Kamenetzky, Rachel R.
A common component of multi-layer insulation blankets is beta cloth, a woven fiberglass cloth impregnated with Teflon. It is planned for extensive use on the International Space Station (ISS). The Environmental Effects Group of the Marshall Space Flight Center Materials, Processing and Manufacturing Department has investigated the impact of atomic oxygen (AO) and ultraviolet (UV) radiation on the optical properties of plain and aluminized beta cloth, both in the laboratory and as part of long-du...
Keywords: NEURAL NETS; HOLOGRAPHY; VIBRATION; MATHEMATICAL MODELS; FINITE ELEMENT METHOD; DAMAGE; EDUCATION; INCENTIVES; VIBRATION MODE
Downloads: 189
[texts]Large Eddy Simulation of a Near Sonic Turbulent Jet and Its Radiated Noise - Constantinescu, G. S.
In this paper numerical simulations are used to calculate the turbulence dynamics simultaneously with the sound field for a high-speed near-sonic (Ma=0.9) compressible jet at two Reynolds numbers of 3,600 and 72,000. LES (Large Eddy Simulation) in conjunction with accurate numerical schemes is used to calculate the unsteady flow and sound in the near field of the jet. It is shown that the jet mean parameters, mean velocity fields and turbulence statistics are in good agreement with experimental ...
Keywords: FINITE ELEMENT METHOD; ERROR ANALYSIS; CONDUCTIVE HEAT TRANSFER; EQUILIBRIUM FLOW; APPROXIMATION; BOUNDARIES; COLLECTION; ESTIMATING; STEADY STATE
Downloads: 109
[texts]Use of the Terminal Area Simulation System (TASS) to study microburst wind shears - Byrd, Gregory P
Ground-based and airborne Doppler radar and LIDAR systems are being designed to alert pilots when a hazardous windshear is present. A key element in this design effort is understanding the microburst itself. This is accomplished by means of the TASS model which was developed for NASA by Proctor (1987a,b). The time-dependent TASS model has two vesions: a two-demensional high resolution axisymmetric model, and a three-demensional model...
Keywords: CYLINDRICAL BODIES; FINITE ELEMENT METHOD; GRID GENERATION (MATHEMATICS); HEAT TRANSFER; MESH; OPTIMIZATION; STIFFNESS MATRIX; THERMAL CONDUCTIVITY
Downloads: 94
[texts]Dot Projection Photogrammetric Technique for Shape Measurements of Aerospace Test Articles - Jones, Thomas W.
Results from initial laboratory investigations with the dot projection photogrammetric technique are presented for three wind-tunnel test articles with a range of surface scattering and reflection properties. These test articles are a semispan model and a micro air vehicle with a latex wing that are both diffusely reflecting, and a highly polished specularly reflecting model used for high Reynolds number testing...
Keywords: FORCE DISTRIBUTION; STRUCTURAL DESIGN; DESIGN OPTIMIZATION; EXPERIMENT DESIGN; COMPUTERIZED SIMULATION; FINITE ELEMENT METHOD; DYNAMIC RESPONSE
Downloads: 82
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